Creación de un ViewModel para Seguimiento de Localización en Android

Implementing the logic for real-time position tracking in your Android application is possible through an organized ViewModel. Using the integration with Hilt and Kotlin's reactive flows(StateFlow and Flow), you can easily manage the observability of your location and the dynamic handling of permissions within the Android ecosystem.

How to configure a ViewModel with Hilt for Maps?

Configuring the ViewModel starts by integrating it with Hilt using the @HiltViewModel annotation. Essential dependencies, such as a LocationTracker, will be easily injected and allow you to efficiently monitor location-related states.

• Create a new TrackingMapViewModel.
• Use the @HiltViewModel annotation.
• Declare dependencies as LocationTracker.
• Manage states using variables of type MutableStateFlow.

What variables are needed to manage location states?

There are key variables that will allow you to check permissions and control whether the tracking should be triggered or stopped at any time:

• HasLocationPermission: defines whether the application has the necessary permissions.
• ShouldTrack: indicates when the location should be tracked, stopped or resumed.
• IsAllowedToTrack: combines the previous variables to automatically trigger tracking.

How to handle tracking states through intentions?

Managing the actions that affect the location tracking policy is handled throughIntents. These are used to modify the internal tracking state in the ViewModel:

• ResumeTracking: activates monitoring(ShouldTrack = True).
• PauseTracking: stops temporarily the monitoring(ShouldTrack = False).
• StartTracking: starts for the first time the location monitoring(ShouldTrack = True and activate tracking in LocationTracker).

How to connect the ViewModel with the map interface?

The interface must react to the change of state reflected in the ViewModel. You must integrate that state into your screen using Compose:

• Create a MapScreen map screen.
• Bind the state of the ViewModel in Compose using collectAsState().
• Ensure that interface actions (such as floating buttons) correctly dispatch intentions to the ViewModel.

How to resolve common location-related errors?

A common error is to leave observability enabled from previous code used for testing or previous exercises. To solve this:

• Check MainActivity for the presence of old code and remove it.
• Make sure to activate correctly the location permissions from the device configuration.
• Restart the emulator or device to correctly validate the expected behavior.

This tidy approach allows to build a professional tracking system easily extendable and reusable in multiple applications.